In order to miniaturize a unit, a structure in which a motor control circuit (inverter) is integrated with an electric motor is known. In such a structure, since a power line for connecting the motor and the inverter is short, heat from a motor coil is easily conducted to the inverter via the power line. There is a possibility that a semiconductor element within the inverter is broken down in a case where the amount of conducted heat becomes larger.
Therefore, JP2010-268633A discloses a structure for cooling a power line. Specifically, a terminal base that connects an inverter power line to a motor power line is connected to a cooler in which a water passage is incorporated via an L-shaped heat transfer member. One flat plate part (a first flat plate part) of the L-shaped heat transfer member is adhered and fixed to a surface of the cooler that is separated from the water passage. A second flat plate part that is orthogonal to the first flat plate part is adhered and fixed to the terminal base. The inverter power line is fastened by a bolt to the terminal base so as to sandwich the second flat plate part therebetween.